This invention relates to a magnetic head slider and a material therefor. More particularly, it is concerned with such magnetic head slider for recording and reproducing information to be used in computers, audio-visual appliances, video tape recorders, and so forth, as well as materials for such magnetic head slider and materials for wear-resistant functional component members for magnetic tapes.
For such magnetic head slider for recording and reproducing information, there have so far been used polycrystalline Ni-Zn ferrite, Mn-Zn ferrite, single crystal Mn-Zn ferrite, high hardness permalloy, and so on.
Nowadays, improvement in the recording density and wear-resistant property in the magnetic recording has been so ardently desired, and, for satisfying such desire, technique of forming a thin film magnetic head has been much more attempted. With the progress in such thin film magnetic head, selection of the optimum materials has been made to satisfy the characteristics required of each of the materials for the magnetic circuit members for the recording and reproduction, and material for the wear-resistant magnetic head slider.
In more detail, it has been contemplated to be desirable to use, as the material for the magnetic circuit, thin films of permalloy, sendust or amorphous materials which have excellent magnetic characteristic in the high frequency band, while, as the material for the functional component members which are required to have the wear-resistant property, alumina type materials.
The materials for such wear-resistant sliding member are primarily non-magnetic, but they are required to have various properties such as the wear-resistant property, precision-machinability (or grindability), machining efficiency, high mechanical strength, high density of the material structure, compatibility with the recording medium, lubricating property, thermal matching with metal thin film, and others.
"Al.sub.2 O.sub.3 -TiC" composite material as disclosed in Japanese Patent Kokai Publication No. 55-163665 as the material for the magnetic head slider is excellent in its various properties and has therefore been regarded up to the present as one of the most suitable material for such wear-resistant functional members. This material, however, can in no way be said to be a stable material in respect of its compatibility with the recording medium, lubricating property, and precision machinability (in particular, machining yield).
Japanese Patent Kokai Publication No. 57-198578 proposes TiO.sub.2 -Al.sub.2 O.sub.3 type materials for the magnetic head slider, in which the compatibility with the recording medium and the lubricating property thereof have been improved in contrast to those of the Al.sub.2 O.sub.3 -TiC material. The materials have excellent characteristics in many aspects, and, therefore, they are considered to be one of the most suitable materials for the wear-resistant functional component members in the magnetic head slider. However, the materials still have their own points of problem such that they are inferior in their machinability, mechanical properties (in particular, poor machining yield).
Furthermire, Japanese Patent Kokai Publication No. 60-171617 proposes, as the material having its improved property in chipping during the slicing step, a ceramic substrate for the thin film magnetic head which consists principally of zirconia. However, with the material composed of a partially stabilized ZrO.sub.2 as the principal component, there still remain such problems that it readily undergoes thermal deterioration, and that the monoclinic crystals increase due to heating to a temperature level of several hundreds degrees Centigrade and subsequent cooling at the time of forming such thin film onto the substrate, with the consequent problems of the substrate such as deterioration in its mechanical strength and warping due to volume change.
When such tough ceramic is used as the materials for the magnetic head slider, its machining into a complicated configuration becomes difficult owing to its poor machinability.